Could Rubio save the GOP ticket?

Maybe, but it won't be because he's Latino.

Florida's new Republican senator, 40-year-old Marco Rubio, is handsome, personable and smart. He can talk with intelligence and ease about foreign policy, the federal budget and the aspirations of the American people. And he has a Reaganesque gift for sounding reassuring, even when he's arguing for Tea Party positions such as a complete overhaul of Social Security and Medicare.

All these factors, along with his decisive electoral victory last year in Florida, one of the most important swing states in a presidential election, have vaulted Rubio to the top of the GOP's list of potential vice presidential candidates, no matter who the party's presidential nominee turns out to be.

A big piece of that enthusiasm, of course, stems from the hope that Rubio would help the party make inroads with the fastest-growing ethnic group in America, Latinos, who have mostly turned a cold shoulder to the party. With Rubio's help, GOP strategists are hoping a whole list of swing states, including not only his native Florida but also Colorado, Arizona and New Mexico, will be tipped into the Republican column.

But does Rubio really hold the Republican Party's key to millions of Latino voters in swing states? Outside Florida, many Latinos don't even know who he is yet. And the evidence suggests that, once they do, Rubio will have an uphill climb despite his Hispanic name.

Most years, Latinos are strongly in the Democratic camp. In the 2008 election, for example, Barack Obama won about two-thirds of the Latino vote, according to the Pew Hispanic center. (He won only 43% of the non-Hispanic white vote.) While Latinos tend to be moderate or conservative on social issues, they poll as quite liberal on economic issues — like the federal government's role in providing a safety net for those in need.

Rubio, by contrast, has grown more conservative over the course of his career, and today he is a thoroughgoing small-government conservative — a Tea Party man.

His priority, he says, is to shrink the federal government, reduce taxes and get out of the way of the free enterprise system. He's praised the proposal of Rep. Paul Ryan (R-Wis.) to transform Medicare into a system that would provide vouchers to help the elderly buy private health insurance.

In an interview this week, Rubio reaffirmed one of the most powerful lines in his speeches, that he believes in "a compassionate America." But when I asked him what the government's role was in ensuring that compassion, he said most of the action should come from the private sector.

He did acknowledge "a place for a safety net," noting that "you can't ask an 80-year-old to get up and get a job." But he thinks social programs need more cost controls. "You can't give away money you don't have," he said.

So one act of compassion, he added, would be reforming Medicare to keep its costs from spiraling out of control.

"The single biggest driver of our national debt is a Medicare program that will disappear if it continues as it is now," he noted. "It's irresponsible."

Those are all respectable positions — especially inside the Tea Party. But they're not that likely to win support from Latino voters in states like Colorado and New Mexico. When a GOP think tank called Resurgent Republic polled Latinos in those states in September, solid majorities said they thought the best way to improve the economy would be "to increase government investments in job training, education and infrastructure."

On immigration, too, Rubio has grown out of step with a majority of Latinos. He won national attention this fall when he warned Republican presidential candidates that their competition to sound tough on illegal immigration risked making them sound hostile to many Latinos. But his critique of his party's positions was limited mostly to its tone, not its substance.

Rubio told me he would support some kind of Dream Act, which would allow illegal immigrants who came to the United States as children to qualify for citizenship if they complete two years of college or military service. But only after the southwestern border is secured, enforcement of immigration laws is increased and the legal immigration system is fixed — which is another way of saying, not any time soon.

As for state laws in Arizona, Alabama and Georgia that direct local police to check the immigration status of anyone they pull over for a traffic offense whose citizenship appears dubious, Rubio is staying with the GOP line. "Those states have the right to do these things. The federal government wasn't enforcing the law," he said.

Rubio's history in Florida politics also suggests that his sway over Latino voters isn't guaranteed. He's wildly popular among the state's Tea Party conservatives — but only modestly popular among the state's Latinos.

In a recent Resurgent Republic poll, 51% of Florida Latinos said they had a favorable view of Rubio — but slightly more, 55%, said they had a favorable view of Obama. And that's in Florida, where Cuban Americans, who tend to be more conservative than other Latinos, make up about a third of the state's Latino population. In other words, many of Rubio's home-state voters, who know him best, appear to view him as a Tea Party conservative who happens to be Latino, rather than the other way around.

Rubio is himself Cuban American, which makes him a minority among the nation's Latinos, most of whom are Mexican American. (Only about 4% of U.S. Latinos are of Cuban ancestry.)

The GOP argues that this isn't a fatal handicap. "Rubio's story — his mother worked in a hotel, his father tended bar — is an inspiration to a lot of people, not just Cuban Americans," argues Hector Barajas, a GOP strategist in Sacramento. But it's not a plus, either.

In the end, it may not be Rubio's ethnicity that boosts him with GOP voters but something else: He embraces staunch Tea Party principles, but he doesn't come off as a zealot. He's Michele Bachmann, but not as scary.

If Republicans nominate a candidate who needs to shore up support on the party's right — a candidate like, say, Mitt Romney — Rubio could be exactly what's needed. He could give Tea Party activists a reason to turn out at the polls even if the presidential nominee isn't their first choice. But as a way to guarantee a big defection of Latino votes to the GOP column, he's no sure thing.